Primes and targets in rapid chases: Tracing sequential waves of motor activation.

Single-cell recordings have indicated that visual stimuli elicit rapid waves of neuronal activation that propagate so fast that they might be free of intracortical feedback. Here, the time course of feedforward activation was traced by measuring pointing responses to color targets preceded by color primes initiating either the same or opposite response. The early time course of priming effects was strictly time locked to prime onset and depended only on properties of the primes, but was independent of the onset times of the actual targets as well as the perceptual effects of targets on primes. Results indicated that nonoverlapping feedforward signals by primes and targets traverse the visuomotor system in a rapid chase, controlling associated motor responses in strict sequence. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Psychological Stress Tasks in the Prediction of Blood Pressure Level and Need for Antihypertensive Medication: 9-12 Years of Follow-Up.

Increased blood pressure (BP) reactivity to subtypes of psychological stimuli may differentially predict the development of future BP elevation or hypertension. The authors present the 9-12-year follow-up results of 82 (86%) of 95 male participants with different BP levels. They were healthy, untreated, and age-matched volunteers from a routine health checkup carried out on all 35-, 40-, and 45-year-olds from a medium-sized city. Intra-arterial systolic blood pressure (SBP) during the psychological tasks improved the prediction of future casual SBP and noninvasive 24-hr ambulatory SBP compared with predictions from casual diagnostic measurements. Diastolic blood pressure (DBP) was very useful when added to casual DBP in predicting the need for antihypertensive medication. Reactivity to active tasks especially predicts the need for antihypertensive medication. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A New Approach for Predicting the Final Outcome of Evolution Strategy Optimization Under Noise

Differential-geometric methods are applied to derive steady state conditions for the (μ/μ _I ,λ)-ES on the general quadratic test function disturbed by fitness noise of constant strength. A new approach for estimating the expected final fitness deviation observed under such conditions is presented. The theoretical results obtained are compared with real ES runs, showing a surprisingly excellent agreement.     

Regiocomplementary O‐Methylation of Catechols by Using Three‐Enzyme Cascades

S‐Adenosylmethionine (SAM)‐dependent enzymes have great potential for selective alkylation processes. In this study we investigated the regiocomplementary O‐methylation of catechols. Enzymatic methylation is often hampered by the need for a stoichiometric supply of SAM and the inhibitory effect of the SAM‐derived byproduct on most methyltransferases. To counteract these issues we set up an enzyme cascade. Firstly, SAM was generated from l ‐methionine and ATP by use of an archaeal methionine adenosyltransferase. Secondly, 4‐O‐methylation of the substrates dopamine and dihydrocaffeic acid was achieved by use of SafC from the saframycin biosynthesis pathway in 40–70 % yield and high selectivity. The regiocomplementary 3‐O‐methylation was catalysed by catechol O‐methyltransferase from rat. Thirdly, the beneficial influence of a nucleosidase on the overall conversion was demonstrated. The results of this study are important milestones on the pathway to catalytic SAM‐dependent alkylation processes.     

Water Supply System Performance for Different Pipe Materials Part I: Water Quality Analysis

The quality of potable water has been a major issue in the water industry for the last few decades. The deterioration of treated water can be due to physical, chemical or microbiological changes that occur in the water during distribution. In addition, pipe material and decay of a disinfectant agent can affect the quality of the water being distributed. In this study the purpose was to simulate the decay of chlorine in two networks, one made of old cast iron (CI) pipes and another of polyethylene (PE) pipes. In addition the performance of the network considering chlorine concentration, velocity, water age, and an intrusion of a contaminant – in this case organic material – into the network was evaluated. The simulations were performed with EPANET software using as the simulation network an example network from the program. It was found that the CI network requires higher initial chlorine concentrations than the PE network to maintain the required minimum chlorine concentration throughout the whole network. To maintain the chlorine concentrations required by WHO (Cl must be greater than 0.2 mg/l and lesser than 0.5 mg/l) re-chlorination stations were necessary to add into both networks. The performance of both networks before re-chlorination was low due to high initial chlorine concentrations, but after the addition of the re-chlorination stations it was 100% throughout the networks. The performance of the velocities was good in both networks. The performance of the water age was dependent mainly on the tank usage, and the performance of contamination by organic material depended on the coefficient that defines the decay rate of the organic material in the bulk phase.     

A New Approach to Limit Dextrinase and its Role in Mashing*

Limit dextrinase (EC 3.1.2.41) is a debranching enzyme catalyzing the hydrolysis of α-1,6-glucosidic linkages in starch. The role of this debranching enzyme in beer brewing has been questioned due to its assumed heat lability. In the present work the effectiveness of limit dextrinase was studied under conditions mimicking brewery practice rather than in a buffer solution. It was demonstrated that typical conversion temperatures of 63–65 °C and a mash pH of 5.4–5.5 favour the action of malt limit dextrinase. The temperature optimum for the limit dextrinase of a malt extract was 60–62.5 °C, as opposed to 50 °C for purified limit dextrinase. Lowering the mash pH from 5.8 to 5.4 increased wort fermentability due to increased limit dextrinase activity. Wort fermentability was more strongly correlated to the free limit dextrinase activity of malt than to the α- and β-amylase activities.     

Comparative Neuropharmacology and Pharmacokinetics of Methamphetamine and Its Thiophene Analog Methiopropamine in Rodents

Methiopropamine is a novel psychoactive substance (NPS) that is associated with several cases of clinical toxicity, yet little information is available regarding its neuropharmacological properties. Here, we employed in vitro and in vivo methods to compare the pharmacokinetics and neurobiological effects of methiopropamine and its structural analog methamphetamine. Methiopropamine was rapidly distributed to the blood and brain after injection in C57BL/6 mice, with a pharmacokinetic profile similar to that of methamphetamine. Methiopropamine induced psychomotor activity, but higher doses were needed (E_max 12.5 mg/kg; i.p.) compared to methamphetamine (E_max 3.75 mg/kg; i.p.). A steep increase in locomotor activity was seen after a modest increase in the methiopropamine dose from 10 to 12.5 mg/kg, suggesting that a small increase in dosage may engender unexpectedly strong effects and heighten the risk of unintended overdose in NPS users. In vitro studies revealed that methiopropamine mediates its effects through inhibition of norepinephrine and dopamine uptake into presynaptic nerve terminals (IC₅₀ = 0.47 and 0.74 µM, respectively), while the plasmalemmal serotonin uptake and vesicular uptake are affected only at high concentrations (IC₅₀ > 25 µM). In summary, methiopropamine closely resembles methamphetamine with regard to its pharmacokinetics, pharmacodynamic effects and mechanism of action, with a potency that is approximately five times lower than that of methamphetamine.     

Goniofluorometer for characterization of fluorescent materials

A goniofluorometer has been built that is capable of measuring in various viewing angles ranging from 10 degrees to 90 degrees . The incident angle can be varied from 0 degrees to 8 degrees . The goniofluorometer can measure bispectral luminescent radiance factors in the wavelength range of 250-800 nm. To our knowledge, there are no other reported results of similar devices capable of spectral measurements in various measurement geometries.